AVS 45th International Symposium
    Surface Science Division Monday Sessions
       Session SS2-MoA

Paper SS2-MoA5
Promotion through Gas Phase Induced Surface Segregation: Methanol Synthesis from CO, CO@sub 2@ and H@sub 2@ over Ni/Cu(100)

Monday, November 2, 1998, 3:20 pm, Room 309

Session: Surface Chemistry on Model Catalysts
Presenter: I. Chorkendorff, Technical University of Denmark
Authors: I. Chorkendorff, Technical University of Denmark
J. Nerlov, Technical University of Denmark
Correspondent: Click to Email
The synthesis rate of methanol formation over Cu(100) and Ni/Cu(100) from various gas mixtures of CO, CO@sub 2@ and H@sub 2@ have been studied. It was found that the presence of submonolayer quantities of Ni leads to a strong increase in the rate of methanol formation from mixtures containing all three components whereas Ni does not influence the rate from mixtures of CO@sub 2@/H@sub 2@ and CO/H@sub 2@, respectively. The influence of the partial pressures of CO and CO@sub 2@ on the rate indicates that the role of CO is strictly promoting. From temperature programmed desorption spectra it follows that the surface concentration of Ni depends strongly on the partial pressure of CO. In this way the increase in reactivity was interpreted as a CO-induced structural promotion introduced by the stronger bonding of CO to Ni as compared to Cu. It is suggested that this type of promotional behavior will be of general importance in existent catalysts and perhaps even more relevant in the development of new or improved bimetallic catalyst